Answers to some questions:
How long does a game take to load: Less than a minute usually. If it takes longer, its very unusual, but I have seen a game that takes about 2 minutes to load. Though usually it takes about 30 seconds.
Can you rename the bios to scph1001.bin and should it be lowercase: Yes, and yes. If the BIOS worked with epsxe, it will probably work with PCSX and in turn, work with GP2PSX. Though it may not, so I'm not sure. Let me know if it works.
Also the scph1001.bin BIOS should be located in the same directory as gp2psxxx.gpe
As for compressing ISOs: If you're compressing ISO's, I suggest the .Z format over ZNX as I'm not sure if ZNX files will work with the "wsnd" sound enabled version. To compress ISOs as .Z with PocketISO 2.0, you should try to use the FF8 search method since it rarely finds anything to rip. That's a good thing, since ripping out stuff from the ISO is not recommended for testing. Once you have an ISO loaded Analyed using FF8 search method, and nothing was found, click Process ISO and it should output a .Z and .Z.table file.
Both .Z and .Z.table files are REQUIRED and should be paired in the same directory. You load the .Z file though.
As for MGS, I would like to test it but I don't have the game. Does anyone know if this game works on 0.33 with or without sound version? I too would like to know.
Thanks.